There's been lots of discussion about these strange people who put Chev badges on their Commodores. It's something to do with Australia's cultural cringe and there's no real reason for it as Chevrolet had little to do with the manufacture of a Commodore.

But the opposite happens in the US. Here's an example. A 2014 Chev SS that the owner has exchanged the bow tie for Holden badges.

This makes more sense as these Chevs were, in fact, built by Holden in Australia.